#pragma once
#include <string.h>
#include <memory>
class AES_128
{
	static BYTE sbox(BYTE a)
	{
		static BYTE const sBox[256] =
		{ /*  0    1    2    3    4    5    6    7    8    9    a    b    c    d    e    f */
			0x63,0x7c,0x77,0x7b,0xf2,0x6b,0x6f,0xc5,0x30,0x01,0x67,0x2b,0xfe,0xd7,0xab,0x76, /*0*/
			0xca,0x82,0xc9,0x7d,0xfa,0x59,0x47,0xf0,0xad,0xd4,0xa2,0xaf,0x9c,0xa4,0x72,0xc0, /*1*/
			0xb7,0xfd,0x93,0x26,0x36,0x3f,0xf7,0xcc,0x34,0xa5,0xe5,0xf1,0x71,0xd8,0x31,0x15, /*2*/
			0x04,0xc7,0x23,0xc3,0x18,0x96,0x05,0x9a,0x07,0x12,0x80,0xe2,0xeb,0x27,0xb2,0x75, /*3*/
			0x09,0x83,0x2c,0x1a,0x1b,0x6e,0x5a,0xa0,0x52,0x3b,0xd6,0xb3,0x29,0xe3,0x2f,0x84, /*4*/
			0x53,0xd1,0x00,0xed,0x20,0xfc,0xb1,0x5b,0x6a,0xcb,0xbe,0x39,0x4a,0x4c,0x58,0xcf, /*5*/
			0xd0,0xef,0xaa,0xfb,0x43,0x4d,0x33,0x85,0x45,0xf9,0x02,0x7f,0x50,0x3c,0x9f,0xa8, /*6*/
			0x51,0xa3,0x40,0x8f,0x92,0x9d,0x38,0xf5,0xbc,0xb6,0xda,0x21,0x10,0xff,0xf3,0xd2, /*7*/
			0xcd,0x0c,0x13,0xec,0x5f,0x97,0x44,0x17,0xc4,0xa7,0x7e,0x3d,0x64,0x5d,0x19,0x73, /*8*/
			0x60,0x81,0x4f,0xdc,0x22,0x2a,0x90,0x88,0x46,0xee,0xb8,0x14,0xde,0x5e,0x0b,0xdb, /*9*/
			0xe0,0x32,0x3a,0x0a,0x49,0x06,0x24,0x5c,0xc2,0xd3,0xac,0x62,0x91,0x95,0xe4,0x79, /*a*/
			0xe7,0xc8,0x37,0x6d,0x8d,0xd5,0x4e,0xa9,0x6c,0x56,0xf4,0xea,0x65,0x7a,0xae,0x08, /*b*/
			0xba,0x78,0x25,0x2e,0x1c,0xa6,0xb4,0xc6,0xe8,0xdd,0x74,0x1f,0x4b,0xbd,0x8b,0x8a, /*c*/
			0x70,0x3e,0xb5,0x66,0x48,0x03,0xf6,0x0e,0x61,0x35,0x57,0xb9,0x86,0xc1,0x1d,0x9e, /*d*/
			0xe1,0xf8,0x98,0x11,0x69,0xd9,0x8e,0x94,0x9b,0x1e,0x87,0xe9,0xce,0x55,0x28,0xdf, /*e*/
			0x8c,0xa1,0x89,0x0d,0xbf,0xe6,0x42,0x68,0x41,0x99,0x2d,0x0f,0xb0,0x54,0xbb,0x16  /*f*/
		};
		return sBox[a];
	}

	static BYTE inv_sbox(BYTE a)
	{
		static BYTE const inv_sBox[256] =
		{ /*  0    1    2    3    4    5    6    7    8    9    a    b    c    d    e    f  */
			0x52,0x09,0x6a,0xd5,0x30,0x36,0xa5,0x38,0xbf,0x40,0xa3,0x9e,0x81,0xf3,0xd7,0xfb, /*0*/
			0x7c,0xe3,0x39,0x82,0x9b,0x2f,0xff,0x87,0x34,0x8e,0x43,0x44,0xc4,0xde,0xe9,0xcb, /*1*/
			0x54,0x7b,0x94,0x32,0xa6,0xc2,0x23,0x3d,0xee,0x4c,0x95,0x0b,0x42,0xfa,0xc3,0x4e, /*2*/
			0x08,0x2e,0xa1,0x66,0x28,0xd9,0x24,0xb2,0x76,0x5b,0xa2,0x49,0x6d,0x8b,0xd1,0x25, /*3*/
			0x72,0xf8,0xf6,0x64,0x86,0x68,0x98,0x16,0xd4,0xa4,0x5c,0xcc,0x5d,0x65,0xb6,0x92, /*4*/
			0x6c,0x70,0x48,0x50,0xfd,0xed,0xb9,0xda,0x5e,0x15,0x46,0x57,0xa7,0x8d,0x9d,0x84, /*5*/
			0x90,0xd8,0xab,0x00,0x8c,0xbc,0xd3,0x0a,0xf7,0xe4,0x58,0x05,0xb8,0xb3,0x45,0x06, /*6*/
			0xd0,0x2c,0x1e,0x8f,0xca,0x3f,0x0f,0x02,0xc1,0xaf,0xbd,0x03,0x01,0x13,0x8a,0x6b, /*7*/
			0x3a,0x91,0x11,0x41,0x4f,0x67,0xdc,0xea,0x97,0xf2,0xcf,0xce,0xf0,0xb4,0xe6,0x73, /*8*/
			0x96,0xac,0x74,0x22,0xe7,0xad,0x35,0x85,0xe2,0xf9,0x37,0xe8,0x1c,0x75,0xdf,0x6e, /*9*/
			0x47,0xf1,0x1a,0x71,0x1d,0x29,0xc5,0x89,0x6f,0xb7,0x62,0x0e,0xaa,0x18,0xbe,0x1b, /*a*/
			0xfc,0x56,0x3e,0x4b,0xc6,0xd2,0x79,0x20,0x9a,0xdb,0xc0,0xfe,0x78,0xcd,0x5a,0xf4, /*b*/
			0x1f,0xdd,0xa8,0x33,0x88,0x07,0xc7,0x31,0xb1,0x12,0x10,0x59,0x27,0x80,0xec,0x5f, /*c*/
			0x60,0x51,0x7f,0xa9,0x19,0xb5,0x4a,0x0d,0x2d,0xe5,0x7a,0x9f,0x93,0xc9,0x9c,0xef, /*d*/
			0xa0,0xe0,0x3b,0x4d,0xae,0x2a,0xf5,0xb0,0xc8,0xeb,0xbb,0x3c,0x83,0x53,0x99,0x61, /*e*/
			0x17,0x2b,0x04,0x7e,0xba,0x77,0xd6,0x26,0xe1,0x69,0x14,0x63,0x55,0x21,0x0c,0x7d  /*f*/
		};
		return inv_sBox[a];
	}

	static BYTE GF_TABLE(BYTE a, BYTE b)
	{
		static std::shared_ptr<BYTE> ARRAY[0x10];
		if (!ARRAY[a])
		{
			BYTE src_arry[] = { 1,2,3,0x9,0xb,0xd,0xe };
			for (BYTE& ref : src_arry)
			{
				ARRAY[ref] = std::shared_ptr<BYTE>(new BYTE[256]);
				for (UINT i = 0; i < 256; ++i)
				{
					ARRAY[ref].get()[i] = GF2_8(ref, i);
				}
			}

		}
		return ARRAY[a].get()[b];
	}

	static void add_round_key(BYTE* a, BYTE const * k)
	{
		UINT64* ap = (UINT64*)a;
		UINT64* kp = (UINT64*)k;
		ap[0] ^= kp[0];
		ap[1] ^= kp[1];
	}

	static void sub_bytes(BYTE* a)
	{
		for (UINT64 i = 0; i < 16; ++i)
		{
			a[i] = sbox(a[i]);
		}
	}

	static void inv_sub_bytes(BYTE* a)
	{
		for (UINT64 i = 0; i < 16; ++i)
		{
			a[i] = inv_sbox(a[i]);
		}
	}

	static void shift_rows(BYTE* a)
	{
		for (INT64 i = 1; i < 4; ++i)
		{
			for (INT64 j = 0; j < i; ++j)
			{
				BYTE tmp = a[i];
				for (INT64 r = 0; r <16; r += 4)
				{
					a[i + r] = a[i + r + 4];
				}
				a[i + 12] = tmp;
			}
		}
	}

	static void inv_shift_rows(BYTE* a)
	{
		for (INT64 i = 1; i < 4; ++i)
		{
			for (INT64 j = 4 - i; j > 0; --j)
			{
				BYTE tmp = a[i];
				for (INT64 r = 0; r <16; r += 4)
				{
					a[i + r] = a[i + r + 4];
				}
				a[i + 12] = tmp;
			}
		}

	}

	static BYTE GF2_8(BYTE a, BYTE b)
	{
		BYTE ret = 0;
		BYTE p;
		for (BYTE i = 0; i < 8; ++i)
		{
			if (b & 1) { ret ^= a; }
			p = a & 0x80;
			a <<= 1;
			if (p) { a ^= 0x1B; }
			b >>= 1;
		}
		return ret;
	}

	static void mix(BYTE* a, BYTE const * b)
	{
		BYTE tmp[4];
		for (INT64 i = 0; i < 16; i += 4)
		{
			for (INT64 r = 0; r < 4; ++r)
			{
				tmp[r] = 0;
				for (INT64 j = 0; j < 4; ++j)
				{
					tmp[r] ^= GF_TABLE(b[r * 4 + j],a[i + j]);
				}
			}
			for (INT64 r = 0; r < 4; ++r)
			{
				a[i + r] = tmp[r];
			}
		}
	}

	static void mix_columns(BYTE* a)
	{
		static BYTE const _RECT[] = { 2,3,1,1,1,2,3,1,1,1,2,3,3,1,1,2 };
		mix(a, _RECT);
	}

	static void inv_mix_columns(BYTE* a)
	{
		static BYTE const INV_RECT[] = { 0x0E,0x0B,0x0D,0x09,0x09,0x0E,0x0B,0x0D,0x0D,0x09,0x0E,0x0B,0x0B,0x0D,0x09,0x0E };
		mix(a, INV_RECT);
	}

	static void Pkcs7_padding(BYTE* buff, INT64 len)
	{
		BYTE a = 16 - len % 16;
		memset(buff + len, a, a);
	}

	static INT64 auth_Pkcs7_padding(BYTE* buff, INT64 len)
	{
		for (BYTE i = 1; i < buff[len - 1]; ++i)
		{
			if (buff[len - 1 - i] != buff[len - 1])
			{
				return -1;
			}
		}
		return len - buff[len - 1];
	}

	static void key_ext(BYTE const * key, BYTE* extend_key)
	{
		static BYTE const RC[] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1B, 0x36 };
		memcpy(extend_key, key, 16);
		UINT tmp;
		UINT* w = (UINT*)extend_key;
		for (INT64 i = 4; i < 44; ++i)
		{
			tmp = w[i - 1];
			if (i % 4 == 0)
			{
				tmp = tmp >> 8 | tmp << 24;
				BYTE* ptr = (BYTE*)&tmp;
				for (INT64 x = 0; x < 4; ++x)
				{
					ptr[x] = sbox(ptr[x]);
				}
				ptr[0] ^= RC[i / 4 - 1];
			}
			w[i] = w[i - 4] ^ tmp;
		}
	}
	BYTE					_M_round_key[11][16];
	BYTE					_M_iv[16];
public:
	AES_128() = default;

	~AES_128() = default;

	void set_key(BYTE const * key, BYTE const * iv = nullptr)
	{
		key_ext(key, (BYTE*)_M_round_key);
		if (iv)
		{
			memcpy(_M_iv, iv, 16);
		}
	}

	INT64 cbc_encrypt(BYTE const * in, UINT64 in_len, BYTE* out)
	{
		memcpy(out, in, in_len);
		Pkcs7_padding(out, in_len);
		BYTE const * v = _M_iv;
		INT64 size = ((in_len >> 4) + 1) << 4;
		for (INT64 i = 0; i < size; i += 16)
		{
			BYTE* block = out + i;
			add_round_key(block, v);
			add_round_key(block, _M_round_key[0]);
			for (INT64 j = 0; j < 9; ++j)
			{
				sub_bytes(block);
				shift_rows(block);
				mix_columns(block);
				add_round_key(block, _M_round_key[j + 1]);
			}
			sub_bytes(block);
			shift_rows(block);
			add_round_key(block, _M_round_key[10]);
			v = block;
		}
		return size;
	}

	INT64 cbc_decrypt(BYTE const * in, UINT64 in_len, BYTE* out)
	{
		if (in_len % 16 != 0) { return -1; }
		memcpy(out, in, in_len);
		BYTE const * v;
		for (INT64 i = in_len - 16; i >= 0; i -= 16)
		{
			BYTE* block = out + i;
			v = i ? block - 16 : _M_iv;
			add_round_key(block, _M_round_key[10]);
			inv_shift_rows(block);
			inv_sub_bytes(block);
			for (INT64 j = 9; j > 0; --j)
			{
				add_round_key(block, _M_round_key[j]);
				inv_mix_columns(block);
				inv_shift_rows(block);
				inv_sub_bytes(block);
			}
			add_round_key(block, _M_round_key[0]);
			add_round_key(block, v);
		}
		return auth_Pkcs7_padding(out, in_len);
	}

	INT64 ecb_encrypt(BYTE const * in, UINT64 in_len, BYTE* out)
	{
		memcpy(out, in, in_len);
		Pkcs7_padding(out, in_len);
		INT64 size = ((in_len >> 4) + 1) << 4;
		for (INT64 i = 0; i < size; i += 16)
		{
			BYTE* block = out + i;
			add_round_key(block, _M_round_key[0]);
			for (INT64 j = 1; j < 10; ++j)
			{
				sub_bytes(block);
				shift_rows(block);
				mix_columns(block);
				add_round_key(block, _M_round_key[j]);
			}
			sub_bytes(block);
			shift_rows(block);
			add_round_key(block, _M_round_key[10]);
		}
		return size;
	}

	INT64 ecb_decrypt(BYTE const * in, UINT64 in_len, BYTE* out)
	{
		if (in_len % 16 != 0) { return -1; }
		memcpy(out, in, in_len);
		for (INT64 i = in_len - 16; i >= 0; i -= 16)
		{
			BYTE* block = out + i;
			add_round_key(block, _M_round_key[10]);
			inv_shift_rows(block);
			inv_sub_bytes(block);
			for (INT64 j = 9; j > 0; --j)
			{
				add_round_key(block, _M_round_key[j]);
				inv_mix_columns(block);
				inv_shift_rows(block);
				inv_sub_bytes(block);
			}
			add_round_key(block, _M_round_key[0]);
		}
		return auth_Pkcs7_padding(out, in_len);
	}

};